R01UH0136EJ0210 Rev.2.10
Page 464 of 800
Jul 31, 2012
M16C/64A Group
23. Serial Interface UARTi (i = 0 to 2, 5 to 7)
23.2.9
UARTi Special Mode Register 4 (UiSMR4) (i = 0 to 2, 5 to 7)
STAREQ (Start condition generate bit) (b0)
The STAREQ bit becomes 0 when a start condition is generated.
This bit is used in master mode of I
2
C mode. To set this bit to 1, preset the IICM bit in the UiSMR
register to 1 (I
2
C mode). Do not set this bit to 1 when the IICM bit is 0.
RSTAREQ (Restart condition generate bit) (b1)
The RSTAREQ bit becomes 0 when a restart condition is generated.
This bit is used in master mode of I
2
C mode. To set this bit to 1, preset the IICM bit in the UiSMR
register to 1 (I
2
C mode). Do not set this bit to 1 when the IICM bit is 0.
STPREQ (Stop condition generate bit) (b2)
The STPREQ bit becomes 0 when a stop condition is generated.
This bit is used in master mode of I
2
C mode. To set this bit to 1, preset the IICM bit in the UiSMR
register to 1 (I
2
C mode). Do not set this bit to 1 when the IICM bit is 0.
STSPSEL (SCL, SDA output select bit) (b3)
This bit is used in master mode of I
2
C mode. To set this bit to 1, preset the IICM bit in the UiSMR
register to 1 (I
2
C mode). Do not set this bit to 1 when the IICM bit is 0.
Set the STSPSEL bit to 1 (select start condition/stop condition generate circuit) after setting the
STARREQ, RSTAREQ, or STPREQ bit to 1 (start).
Function
Bit Symbol
Bit Name
RW
STPREQ
RSTAREQ
STAREQ
ACKC
Start condition generate bit
0 : Serial data output
1 : ACK data output
ACK data output enable bit
UARTi Special Mode Register 4 (i = 0 to 2, 5 to 7)
RW
RW
RW
RW
Stop condition generate bit
0 : Clear
1 : Start
0 : Clear
1 : Start
Restart condition generate
bit
0 : Clear
1 : Start
SCLHI
SCL output stop bit
If stop condition is detected,
0 : Do not stop SCLi output
1 : Stop SCLi output
RW
SWC9
RW
ACKD
0 : ACK
1 : NACK
ACK data bit
RW
b7 b6 b5 b4
b1
b2
b3
b0
SCL wait auto insert bit 3
0 : No wait-state/wait-state cleared
1 : Hold the SCLi pin low after the ninth bit
of the SCLi is received
0 : Select serial I/O circuit
1 : Select start condition/stop condition
generate circuit
SCL, SDA output select bit
STSPSEL
RW
Symbol
Address
Reset Value
U0SMR4, U1SMR4, U2SMR4
0244h, 0254h, 0264h
00h
U5SMR4, U6SMR4, U7SMR4
0284h, 0294h, 02A4h
00h
Summary of Contents for M16C/60 Series
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